4,642 research outputs found
Delay-Prioritized Scheduling (DPS) for real time traffic in 3GPP LTE system
Given that the co-existence of multimedia applications will be a norm in the future wireless systems, their quality of service (QoS) requirements need to be guaranteed. This has imposed new challenges in the design of packet scheduling algorithms in these systems. To address those challenges, a new packet scheduling algorithm for real time (RT) traffic in downlink third generation partnership project long term evolution (3GPP LTE) system is proposed in this paper. The proposed algorithm utilizes each user's packet delay information and its instantaneous downlink channel conditions when making scheduling decisions. Simulation results show that the proposed algorithm outperforms opportunistic scheduling and maximum-largest weighted delay first algorithms by maximizing system throughput and satisfying the QoS requirements of the RT traffic. ©2010 IEEE
A Utility Proportional Fairness Radio Resource Block Allocation in Cellular Networks
This paper presents a radio resource block allocation optimization problem
for cellular communications systems with users running delay-tolerant and
real-time applications, generating elastic and inelastic traffic on the network
and being modelled as logarithmic and sigmoidal utilities respectively. The
optimization is cast under a utility proportional fairness framework aiming at
maximizing the cellular systems utility whilst allocating users the resource
blocks with an eye on application quality of service requirements and on the
procedural temporal and computational efficiency. Ultimately, the sensitivity
of the proposed modus operandi to the resource variations is investigated
Securing Real-Time Internet-of-Things
Modern embedded and cyber-physical systems are ubiquitous. A large number of
critical cyber-physical systems have real-time requirements (e.g., avionics,
automobiles, power grids, manufacturing systems, industrial control systems,
etc.). Recent developments and new functionality requires real-time embedded
devices to be connected to the Internet. This gives rise to the real-time
Internet-of-things (RT-IoT) that promises a better user experience through
stronger connectivity and efficient use of next-generation embedded devices.
However RT- IoT are also increasingly becoming targets for cyber-attacks which
is exacerbated by this increased connectivity. This paper gives an introduction
to RT-IoT systems, an outlook of current approaches and possible research
challenges towards secure RT- IoT frameworks
Maximizing Profit in Green Cellular Networks through Collaborative Games
In this paper, we deal with the problem of maximizing the profit of Network
Operators (NOs) of green cellular networks in situations where
Quality-of-Service (QoS) guarantees must be ensured to users, and Base Stations
(BSs) can be shared among different operators. We show that if NOs cooperate
among them, by mutually sharing their users and BSs, then each one of them can
improve its net profit. By using a game-theoretic framework, we study the
problem of forming stable coalitions among NOs. Furthermore, we propose a
mathematical optimization model to allocate users to a set of BSs, in order to
reduce costs and, at the same time, to meet user QoS for NOs inside the same
coalition. Based on this, we propose an algorithm, based on cooperative game
theory, that enables each operator to decide with whom to cooperate in order to
maximize its profit. This algorithms adopts a distributed approach in which
each NO autonomously makes its own decisions, and where the best solution
arises without the need to synchronize them or to resort to a trusted third
party. The effectiveness of the proposed algorithm is demonstrated through a
thorough experimental evaluation considering real-world traffic traces, and a
set of realistic scenarios. The results we obtain indicate that our algorithm
allows a population of NOs to significantly improve their profits thanks to the
combination of energy reduction and satisfaction of QoS requirements.Comment: Added publisher info and citation notic
Fuzzy logic-based guaranteed lifetime protocol for real-time wireless sensor networks
© 2015 by the authors; licensee MDPI, Basel, Switzerland. Few techniques for guaranteeing a network lifetime have been proposed despite its great impact on network management. Moreover, since the existing schemes are mostly dependent on the combination of disparate parameters, they do not provide additional services, such as real-time communications and balanced energy consumption among sensor nodes; thus, the adaptability problems remain unresolved among nodes in wireless sensor networks (WSNs). To solve these problems, we propose a novel fuzzy logic model to provide real-time communication in a guaranteed WSN lifetime. The proposed fuzzy logic controller accepts the input descriptors energy, time and velocity to determine each node’s role for the next duration and the next hop relay node for real-time packets. Through the simulation results, we verified that both the guaranteed network’s lifetime and real-time delivery are efficiently ensured by the new fuzzy logic model. In more detail, the above-mentioned two performance metrics are improved up to 8%, as compared to our previous work, and 14% compared to existing schemes, respectively
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